VMDK: open/read/write for monolithicFlat image
Parse vmdk decriptor file and open mono flat image. Read/write the flat extent. Signed-off-by: Fam Zheng <famcool@gmail.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng
Kevin Wolf
parent
91b85bd388
commit
7fa60fa377
171
block/vmdk.c
171
block/vmdk.c
@ -65,6 +65,7 @@ typedef struct VmdkExtent {
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bool flat;
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int64_t sectors;
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int64_t end_sector;
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int64_t flat_start_offset;
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int64_t l1_table_offset;
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int64_t l1_backup_table_offset;
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uint32_t *l1_table;
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@ -407,9 +408,10 @@ fail:
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static int vmdk_parent_open(BlockDriverState *bs)
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{
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char *p_name;
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char desc[DESC_SIZE];
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char desc[DESC_SIZE + 1];
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BDRVVmdkState *s = bs->opaque;
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desc[DESC_SIZE] = '\0';
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if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
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return -1;
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}
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@ -584,6 +586,144 @@ static int vmdk_open_vmdk4(BlockDriverState *bs, int flags)
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return ret;
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}
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/* find an option value out of descriptor file */
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static int vmdk_parse_description(const char *desc, const char *opt_name,
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char *buf, int buf_size)
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{
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char *opt_pos, *opt_end;
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const char *end = desc + strlen(desc);
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opt_pos = strstr(desc, opt_name);
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if (!opt_pos) {
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return -1;
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}
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/* Skip "=\"" following opt_name */
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opt_pos += strlen(opt_name) + 2;
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if (opt_pos >= end) {
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return -1;
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}
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opt_end = opt_pos;
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while (opt_end < end && *opt_end != '"') {
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opt_end++;
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}
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if (opt_end == end || buf_size < opt_end - opt_pos + 1) {
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return -1;
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}
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pstrcpy(buf, opt_end - opt_pos + 1, opt_pos);
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return 0;
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}
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static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
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const char *desc_file_path)
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{
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int ret;
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char access[11];
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char type[11];
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char fname[512];
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const char *p = desc;
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int64_t sectors = 0;
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int64_t flat_offset;
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while (*p) {
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/* parse extent line:
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* RW [size in sectors] FLAT "file-name.vmdk" OFFSET
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* or
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* RW [size in sectors] SPARSE "file-name.vmdk"
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*/
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flat_offset = -1;
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ret = sscanf(p, "%10s %" SCNd64 " %10s %511s %" SCNd64,
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access, §ors, type, fname, &flat_offset);
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if (ret < 4 || strcmp(access, "RW")) {
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goto next_line;
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} else if (!strcmp(type, "FLAT")) {
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if (ret != 5 || flat_offset < 0) {
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return -EINVAL;
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}
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} else if (ret != 4) {
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return -EINVAL;
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}
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/* trim the quotation marks around */
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if (fname[0] == '"') {
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memmove(fname, fname + 1, strlen(fname));
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if (strlen(fname) <= 1 || fname[strlen(fname) - 1] != '"') {
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return -EINVAL;
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}
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fname[strlen(fname) - 1] = '\0';
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}
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if (sectors <= 0 ||
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(strcmp(type, "FLAT") && strcmp(type, "SPARSE")) ||
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(strcmp(access, "RW"))) {
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goto next_line;
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}
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/* save to extents array */
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if (!strcmp(type, "FLAT")) {
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/* FLAT extent */
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char extent_path[PATH_MAX];
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BlockDriverState *extent_file;
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VmdkExtent *extent;
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path_combine(extent_path, sizeof(extent_path),
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desc_file_path, fname);
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ret = bdrv_file_open(&extent_file, extent_path, bs->open_flags);
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if (ret) {
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return ret;
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}
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extent = vmdk_add_extent(bs, extent_file, true, sectors,
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0, 0, 0, 0, sectors);
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extent->flat_start_offset = flat_offset;
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} else {
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/* SPARSE extent, not supported for now */
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fprintf(stderr,
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"VMDK: Not supported extent type \"%s\""".\n", type);
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return -ENOTSUP;
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}
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next_line:
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/* move to next line */
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while (*p && *p != '\n') {
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p++;
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}
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p++;
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}
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return 0;
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}
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static int vmdk_open_desc_file(BlockDriverState *bs, int flags)
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{
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int ret;
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char buf[2048];
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char ct[128];
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BDRVVmdkState *s = bs->opaque;
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ret = bdrv_pread(bs->file, 0, buf, sizeof(buf));
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if (ret < 0) {
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return ret;
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}
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buf[2047] = '\0';
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if (vmdk_parse_description(buf, "createType", ct, sizeof(ct))) {
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return -EINVAL;
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}
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if (strcmp(ct, "monolithicFlat")) {
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fprintf(stderr,
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"VMDK: Not supported image type \"%s\""".\n", ct);
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return -ENOTSUP;
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}
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s->desc_offset = 0;
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ret = vmdk_parse_extents(buf, bs, bs->file->filename);
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if (ret) {
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return ret;
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}
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/* try to open parent images, if exist */
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if (vmdk_parent_open(bs)) {
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qemu_free(s->extents);
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return -EINVAL;
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}
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s->parent_cid = vmdk_read_cid(bs, 1);
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return 0;
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}
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static int vmdk_open(BlockDriverState *bs, int flags)
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{
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uint32_t magic;
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@ -598,7 +738,7 @@ static int vmdk_open(BlockDriverState *bs, int flags)
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} else if (magic == VMDK4_MAGIC) {
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return vmdk_open_vmdk4(bs, flags);
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} else {
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return -EINVAL;
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return vmdk_open_desc_file(bs, flags);
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}
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}
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@ -679,7 +819,7 @@ static int get_cluster_offset(BlockDriverState *bs,
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if (m_data)
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m_data->valid = 0;
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if (extent->flat) {
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*cluster_offset = 0;
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*cluster_offset = extent->flat_start_offset;
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return 0;
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}
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@ -832,16 +972,20 @@ static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
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/* if not allocated, try to read from parent image, if exist */
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if (bs->backing_hd) {
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if (!vmdk_is_cid_valid(bs))
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return -1;
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return -EINVAL;
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ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
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if (ret < 0)
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return -1;
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return ret;
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} else {
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memset(buf, 0, 512 * n);
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}
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} else {
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if(bdrv_pread(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
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return -1;
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ret = bdrv_pread(extent->file,
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cluster_offset + index_in_cluster * 512,
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buf, n * 512);
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if (ret < 0) {
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return ret;
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}
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}
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nb_sectors -= n;
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sector_num += n;
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@ -865,7 +1009,7 @@ static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
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"(VMDK) Wrong offset: sector_num=0x%" PRIx64
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" total_sectors=0x%" PRIx64 "\n",
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sector_num, bs->total_sectors);
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return -1;
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return -EIO;
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}
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while (nb_sectors > 0) {
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@ -888,16 +1032,17 @@ static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
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n = nb_sectors;
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}
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if (bdrv_pwrite(bs->file,
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ret = bdrv_pwrite(extent->file,
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cluster_offset + index_in_cluster * 512,
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buf, n * 512)
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!= n * 512) {
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return -1;
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buf,
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n * 512);
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if (ret < 0) {
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return ret;
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}
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if (m_data.valid) {
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/* update L2 tables */
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if (vmdk_L2update(extent, &m_data) == -1) {
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return -1;
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return -EIO;
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}
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}
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nb_sectors -= n;
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